Sulfur containing pseudoaromatic detergents



United States Patent 3,364,232 SULFUR CONTATNING PSEUDOAROMATICDETERGENTS Donald .1. Anderson, San Anselmo, Calif-1, assignor t0Chevron Research Company, San Francisco, Calif., a corporation ofDelaware No Drawing. Filed Jan. 5, 1966, Ser. No. 518,787 Claims. (Cl.260-327) This invention concerns novel pseudo-aromatic sulfur containingcompounds and their use as detergents in lubricating oils. Moreparticularly, this invention concerns relatively high molecular weighthydrocarbon substituted pseudo-aromatic compounds having annular sulfurand their use as detergents in lubricating oils.

Trithiones are a peculiar type of pseudo-aromatic system in having onlyone double bond in a five-membered ring and the inability to introduce asecond conventional double bond. Trithione compounds are readilyprepared by the reaction of olefins having at least one methyl group andhave been reported for a variety of uses. See, for example, U.S. PatentNos. 2,535,705 and 2,658,900. However, for the most part, the trithioneshave been of relatively low molecular weight. The most commonly reportedtrithiones in the patent literature have been the trithiones ofisobutylene and diisobutylene.

It has now been found that trithiones having a molecular weight of atleast about 500 and a hydrocarbon alkyl substituent of at least about 30carbon atoms can be prepared and find use as detergents in lubricatingoils. Generally, the trithiones will have molecular weights of less than5,000 and usually less than 3,000.

For the most part, the trithiones of this invention will have thefollowing formula:

wherein R and R have a total number of carbon atoms in the range of 30to 325, at least one being aliphatic hydrocarbon and the other beinghydrogen or aliphatic hydrocarbon: usually one of R and R is analiphatic hydrocarbon group of from about 30 to 325 carbon atoms, moreusually from about 50 to 125 carbon atoms and the other may be hydrogenor lower alkyl. The total molecular weight is in the range of about 500to 5,000, more usually about 750 to 3,000.

Generally, the compositions of this invention will come within thefollowing formula:

ss wherein R is an aliphatic hydrocarbon group of from about 30 to 325carbon atoms, preferably from about 50 to 175 carbon atoms andparticularly preferred from about 50 to 125 carbon atoms, and R is loweralkyl of from 1 to 6 carbon atoms or hydrogen, usually methyl.

The aliphatic hydrocarbon substituents may be derived from a variety ofsources, may be branched chain or straight chain, and while they mayinclude cycloaliphatic groups, for the most part they will be acyclic.

Sources of hydrocarbons having the necessary number of carbon atomsinclude petroleum fractions, polymers of olefins of from about 2 to 6carbon atoms, more usually from about 2 to 5 carbon atoms, e.g.,propylene, isobutene, butenes, 4-methyl-1-pentene, etc.

The preferred aliphatic hydrocarbons are those derived from olefins offrom about 3 to 4 carbon atoms, i.e., propylene and isobutylene; thatis, polymers which are branched chain. Of course, ethylene may becopolym- 3,364,232 Patented Jan. 16, 1968 erized with olefins of ahigher number of carbon atoms to provide branched chain aliphatichydrocarbon groups.

Illustrative compounds include S-n-alkyl trithione, 5- polypropylenetrithione, 5-polyisobutylene trithione, 5- (copolymer of ethylene andisobutylene prepared by the cationic polymerization of4-methylpentene-l) trithione, 4-methyl polyisobutylene trithione, etc.

If desired, the trithione may be oxidized with a peroxidic compound toform the S-oxy trithione. This compound is believed to have thefollowing formula:

wherein R and R are as defined previously.

The following formula:

wherein R and R are as defined previously and X is either a pair ofunshared electrons or coordinately bonded oxygen, may be consideredgeneric to the trithione and its oxy derivative.

While the trithiones of low molecular weight are readily prepared bycontacting sulfur with an olefin of the following basic structure:

or a compound which fulfills the function of an olefin in the reaction,e.g., an aliphatic ketone, it is found that with the high molecularweight polyolefins, e.g., polyisobutylene, a low molecular weighttrithione must be present in order to obtain the trithiones of thisinvention. That is, the high molecular weight olefin, i.e., of at least30 carbon atoms, is contacted with sulfur in the presence ofapproximately equimolar amounts of the high molecular weight olefin anda trithione of from about 4 to 16 carbon atoms, preferably of from about8 to 12 carbon atoms and from about a 5 to weight percent excess of thestoichiometric amount of sulfur and the mixture heated at temperaturesin excess of 175 C. and generally less than 275 C. for periods rangingfrom about 2 to 24 hours. By distilling off the low molecular weightmaterials, the desired trithione compound may be directly isolated.

The oxy derivative may then be prepared by dissolving the trithione in asuitable inert solvent, e.g., benzene, and then adding hydrogen peroxideat ambient temperatures in the presence of a hydroxylic organic solvent,e.g., methanol, acetic acid, etc.

The product formed as described above may then be used in a variety oflubricating oils as detergents.

The following examples are offered by way of illustration and not by wayof limitation.

Example I Into a reaction flask in a nitrogen atmosphere was introducedg. (5 gram atoms) of sulfur and 260 g. of 4 neopentyl 5 tert.buty1 1,2dithiol-3-thione, the mixture heated at 200 C. in a nitrogen atmosphere,and 900 g. (approximately 1 mole) of polyisobutylene added over a periodof about an hour. The temperature was maintained for 12 hours, at theend of which time the temperature was raised to 210 C. and the pressurereduced to about 4-5 mm. Hg and any volatile material distilledoverhead. The residue Weighed 1,028 g. Analysis: S=10.0, 10.1. Aninfrared spectrum of the product was consistent with the trithione.

3 Example 11 Following the procedure of Example I, 900 g. ofpolyisobutylene (approximately 1 mole), 160 g. of sulfur (5 gram atoms),and 260 g. of the same low molecular excellent compatibility with oils.As concentrates, the compounds of this invention Will generally rangefrom about 20 to 80 weight percent of the total composition, moreusually from about 40 to 70 weight percent.

weight trithione (approximately 1 mole) were mixed in 5 Ahmhenped h pcompolmds of .thls ma nitrogen atmosphere. At the end of the heatingperiod, ventlon m lubncatmgk 011s g fg g the temperature was raised to250 C. and the pressure ggg f hgg gg :2; i5 s gzig g h h f to 3 Theresidue welghed 766 Analy' drocarbyl groups are from about 4 to 36carbon atoms. SIS. S- 6.5.

1O (Hydrocarbyl 1s a monovalent organic radical composed Example Insolely of carbon and hydrogen which may be aliphatic, alicyclic oraromatic, or combinations thereof, e.g,, Into a reactlon flask wascharged 9 (approx? aralkyl.) Instead of zinc, an alkyl group orpolyethylenemately 1.5 moles) of polyisobutylene trithione (approx1- Oxygroup may also be used Generally, the hydrocarbyl mately 8 weightpercent sulfur) and 1.5 liters of benzene groups will be alkyl oralkaryL and Stirred While 170-3 (FIPPIOXimateIY moles) The lubricatingfluids which may be used with the f hydrogen Peroxide (3O Welght Percehtaqueous h compounds of this invention (hereinafter referred to as mm)was addefl Over a hh mlhutes' The oils) may be derived from natural orsynthetic sources. ture was then stirred for an additional 2.5 hours,followed Oils generally have viscosities of from about to 50,000 by theaddition of ml. of methanol. When t appeared 20 saybolt Universalsgconds (SUS) at Among that no reaction had occhrredir 10 of acetlocacid a natural hydrocarbonaceous oils are paraflin base, naphadded andfhitemperathre ,lhcreased to 58 Thls thenic base, asphaltic base andmixed base oils. Illus- Seemed to lhlhate the macho, the hempehature wastrative synthetic oils are: hydrocarbon oils, such as polyallowed todrop to 50 C. and the reaction mixture then mars of various olefins,generally of from 2 to 8 carbon held at that temperahhewhen no furtherreachoh h 25 atoms, and alkylated aromatic hydrocarbons; and non- Pearedto be occhmhgr the Prhdhct was f with hydrocarbon oils, such aspolyalkylene oxides, aromatic water and thehrganlc Phase dned sodhhhSulfate ethers, carboxylate esters, phosphate esters and silicon hhelhdand smpped m h The residue Weighed esters. The preferred media are thehydrocarbonaceous Proxhhately 1,300 Ahalysls: S=10hmedia, both naturaland synthetic.

30 The above oils may be used individually or together, Example IVwhenever miscible or made so by the use of mutual sol- (A) Into areaction flask was introduced 260 g. (1 Vent5- mole) of polyisobutylenetrithione and 370 g. (10 g. Other additives may also be included in theoils such atoms) of sulfur, and the reaction flask flushed with nitrovas pour point depressants, oiliness agents, antioxidants, gen. Themixture was then heated to 200 C. and 900 g. 39 rust inhibitors, etc.Usually, the total amount of the addi- (2 moles) of polyisobutyleneadded over a period of 7 tives will range from about 0.1 to 10 weightpercent, more hours. Heating was continued at the same temperatureusually from about 0.5 to 5 weight percent. The individual for a further14 hours. Volatile materials were then readditives may vary from about0.01 to 5 weight percent. moved by heating the mixture to 240 C. with astream 49 In order to demonstrate the excellent effectiveness of ofnitrogen bubbling through the mixture. The product the compounds of thisinvention as detergentsand disweighed 770 g. Analysis: S=12.7, 12.9;molecular persants in lubricating oils, the compounds prepared wereweight (ThermoNAM-Difierential Vapor Pressure Techtested in the 1GCaterpillar Test (MIL-L45 199 condinique)':770. tions). The oil used wasa Mid-Continent SAE 30 oil and (B) The above procedure was repeatedusing the same r 12 mm./ kg. of zinc di(alkylphenyl) phosphorodithioateamount of materials. The product weighed 806 g. (the alkyl groups werepolypropylene of about 12 to 15 Analysis: S=13.1, 13.2; molecular weight(Thermocarbon atoms) was included. The test was carried out NAM)'=69l.for hours and in some instances 120 hours. The fol- As alreadyindicated, the compounds of this invention lowing table indicates theresults.

TABLE I 60 Hours 120 Hour Wt. percent Example of detergent in oil Groove1 Land 2 Underhead 3 Groove Land Underheatl composition DepositsDeposits Deposits Deposits 5 15- 3+0 100- 5-10 7.5 87-7-3-2 440330-3003.3 10 21- sec 05- 0-0 7. 5 5l8-00 405- 55- 30 5.6

1 Groove deposits arerated on a scale of 0 to 100, 0 being completelyclean and 100 being completely filled.

2 Land depoists rated on a scale of 0 to 800, 0 being completely cleanand 800 being completely bla 3 Underhcad rated on a scale of 0 to 10, 0being completely black and 10 being completely clean. 4 The results wereobtained in the absence of any zine'dithiophosphate in the oil.

find use as dispersants and detergents in lubricating oils. They are ofparticular value in diesel engines, demonstrating excellent resultsunder the high temperatures at which diesel engines operate. Whencompounded with a lubricating oil for use in an engine, the compounds ofthis invention will be present in at least about 0.1 weight percent andusually not more than 20 weight percent, more usually in the range ofabout 2 to 15 weight percent. The detergents of this invention may beused with other detergents or by themselves. The compounds of thisinvention can be prepared as concentrates due to their As will beevident to those skilled in the art, various.

modifications on this invention can be made or followed, in the light ofthe foregoing disclosure and discussion, without departing from thespirit or scope of the dish closure or from the scope of the followingclaims.

5 What is claimed is: 1. A composition having a molecular weight in therange of 750 to 3,000 and of the formula:

R2C=CR1 wherein R and R are alkyl or hydrogen, at least one of R and Rbeing alkyl.

2. A composition according to claim 1, wherein R and R have a total offrom 50 to 125 carbon atoms.

3. A composition according to the formula:

of from 50 to 175 carbon atoms, at least one of R and R being alkyl.

H(ii=&-CH: with sulfur in from 5 to 100 percent excess of thestoichiometric amount of sulfur required, in the presence of a trithioneof from 4 to 16 carbon atoms.

References Cited UNITED STATES PATENTS 2,653,910 9/1953 Airs et al.260-327 JAMES A. PATTEN, Primary Examiner.

J. D. RANDOLPH, Assistant Examiner.

1. A COMPOSITION HAVING A MOLECULAR WEIGHT IN THE RANGE OF 750 TO 3,000AND OF THE FORMULA: 3-(S=),4-R1,5-R2-2H-1,2-DITHIOLE WHEREIN R1 AND R2ARE ALKYL OR HYDROGEN, AT LEAST ONE JOF R1 AND R2 BEING ALKYL.